The present invention relates to a semiconductor data processing device having an arrangement for enabling domain setting of resources for each central processing unit (CPU) included therein, and also relates to a data processing system using the semiconductor data processing device. More particularly, the present invention pertains to a semiconductor data processing device technique that is effectively applicable to such a semiconductor device as a system-on-chip (SOC) microcomputer to be embedded in an automotive electrical/electronic apparatus, for example.
In an SOC microcomputer having dual-core CPUs or the like wherein each of the CPUs is run under control of an operating system (OS) thereof on the basis of asymmetric multiprocessing (AMP), there arises a disadvantage that reliability tends to decrease due to such an adverse condition as resource contention by the CPUs or mutual error-induced influence on the CPUs. A well-known technique for obviating this disadvantage is to set up a domain for each CPU in a fashion that each access area is protected hardware-wise, i.e., to implement so-called “domain separation” applicable for enhancement in reliability.
For example, in Patent Document 1 indicated below, there is disclosed a domain separation technique wherein an illegal address access blocking mechanism is disposed between a bus master device and a bus, and wherein the illegal address access blocking mechanism is arranged to have a register for setting up an access permission address range. In the above arrangement, a comparator judges whether an address output at an address line is within the access permission address range, and then, if the address output at the address line is not within the access permission address range, a control line output is disabled for blocking against an illegal access attempt.
In Patent Document 2 indicated below, there is disclosed another domain separation technique wherein a plurality of virtual machines and virtual machine managers that carry out user programs under control of respectively different operating systems are provided to arrange selective configuration of central processing units according to setting information specified in a mode register, and wherein a resource access management module is provided for managing access to hardware resources sharable by the virtual machines. In the above arrangement, the resource access management module receives the setting information specified in the mode register and access control information regarding access from each central processing unit to a hardware resource, and then the resource access control module compares the information thus received with control register setting information. Thus, permission/inhibition control is performed for access to the hardware resource based on the access control information.